FutureBox: DIY analog filterbox

This filterbox was made for Futurewave. It is a dual unit with 2 types of filters, in a desktop format.

- Minimoog Model D VCF, with CV in
- EMS VCS3 type VCF, with CV in
- 2 LFOs, for each filter, with speed select switch, and modulation amount
- 2 fuzz/distortion unit, for each filter, with bypass switch
- 2 preamps, with overdrive
- mixer
- filter bypass switch


My modded Minibrute is for sale

I've modded my Arturia Minibrute with 8 special output jacks, these are on the right side panel.

It's ideal for modular synthesizer central controller.

Special outputs:
  • LFO Sine waveform out
  • LFO stepped waveform out
  • VCA ADSR envelope out
  • VCF ADSR envelope out
  • Arpeggiator clock out (you can sync sequencers to it)
  • Pitch bend wheel CV out
  • Mod wheel CV out
  • Keyboard aftertouch CV

If you're interested, please check out this Ebay auction.


VCO and waveshapers

Here is my new DIY VCO and waveshaper module.

It contains the following circuits:
- 2x Yusynth VCOs
- 2x Suboscillators (for each VCO), with square output (-1, and -2 octaves), based on a 4024 divider circuit
- YuSynth/Jürgen Haibe Wavefolder
- Ian Fritz 5pulser waveshaper

Some pictures:

Demo video of the waveshapers:


Protostar Monosynth

Protostar patchable monosynth

New year, new progress, and a little blog redesign! :)

The instrument shown on the pictures is the Protostar patchable monosynth. It's a usable, but work in progress synth, with the following features:
  • 2 VCOs
  • 2 suboctave generator with square waveform, -1/-2 octave
  • Waveform mixer with noise (4 waveforms/VCO + sub) with gain to overdrive the VCF
  • Minimoog VCF clone
  • 2 VCLFOs with 4 waveform outputs.
  • 2 ADSRs (one for the VCF, one for the VCA)
  • 3 VCAs

The signal path is normalized, based on the traditional VCO-VCF-VCA signal routing of the classic monosynths. The LFOs is modulating the VCO's PWM, the ADSRs is dedicated to the VCF/VCA. All of the signals can be separated, all of the modules are possible to disconnect, thanks to the switching jacks.

Almost all of the modules are based on the great YuSynth designs, so thanks fly to Yves Usson!

Planned modules: Midi2CV (normalized to the VCO/ADSRs), mixers, multiples, external input preamp.

The front panels are laser engraved, made from anodized aluminum. The case is temporary.


Drum synthesizer - Finished

The case is ready, and all functions are working! :) There are small problems, but I will fix them soon.

It's really fun to play with it, especially the cross-modulation functions, and the triggering combined. It can produce sounds from funny, and simple synthetic "space" drum sounds, to agressive, and noisy, industrial drums, even cool analog bass sounds, and simple synth sequences! So much possibilities are in this "simple" instrument. :)

A little summary of the instrument:

Rebel D2 logo

Analog drum machine, and filterbox.

  • Two independent drum channels, based on Coron DS8 design.
  • Two Wasp VCF clones, with LP/HP/BP/Notch modes
  • External signal processing with the filters
  • Triggering with button, or external signal (audio, piezo pulse, etc.), led indicator
  • Inputs for VCO frequency CV
  • VCO frequency modulation (or cross-modulation), with VCF output of the other channel
  • VCF CV input
  • Separate outputs, or mixed out

Sound samples will follow soon!


New modular case

This is the end of the lifecycle of my old, temporary case! Hooooraaay! :) Here is the new one!

I wanted to separate the PSU, and move out of the modular's box. My PSU is too strong, to power only one case, and the modules can occupy more space, if the PSU is not built into the case.

My new panel format is a nonstandard 160x160 mm, this case is built for them. The old modules will be cut to this size, or if it's not possible, they will be converted/reassembled soon.

Cheap materials.

The frame assembled.

Old, and new.

The PSU box, painted with a solar flare.

The new case, painted.

Populated with some modules.


My first multitracked "music" with the DIY modular

In this song i've used the following YuSynth modules: VCOs, EMS VCF, ADSRs, a mixer, and a VCA.


Magic Smoke 8K LFO

For the next module, which I want to build, i've needed a simpe LFO with speed control only. After hours of browsing the schematics, i've found Tim Servo's MSE 8K LFO. This circuit can do triangle and square waveforms, and it's high range, but with only one pot it's hard to fine tune on the lower end. The schematics shows a fine tune pot, but i don't want to include it, because of the limited front panel space.
It's very easy to build, only a TL072 or 074 opamp is needed. I've integrated a simple led driver too.
With polyester caps, the triangle waveforms are perfect, of course ceramics don't do it very well.
My version uses 1nF timing caps, and this gives 15 sec with the lowest pot setting, which is perfect for me.

More schematics, simple LFO's, and waveshapers for this LFO are here.

Thanks to Tim Servo, for his great work!

Dual LFO's on breadboard
Only a 1M Log pot, and an LED

Some power distributors added


My new module: Mixer, MidiCV

This is a combined module, which contains a 6 input mixer, a monophonic Midi2CV converter (MCV-628), and an input preamp.

My new, non-standard panel format is 160x160 mm, fixed. I've bought a 20 aluminium panels, and I will repanel the old blue modules. I need to do this, because the old panels are weak, and inaccurate.


Drum synthesizer - construction 3

The front panel is ready, and the drum synth has a new PSU too. The electronics is completed, now I need to design a case.